Active system for optimization and plugging avoidance of seed/fertilizer in transport conducts

ABSTRACT

An agricultural implement has a product supply chamber, and a pair of transversely extending product delivering booms, each with a plurality of conduits of varying lengths terminating in product distributing nozzles. A fan supplies air to a mixing chamber which also receives product from the supply chamber providing an air entrained flow of product to each conduit. A controller monitors product delivery and controls implement operation. Each conduit has a pressure tap near the nozzle for providing the controller with a pressure differential indication. The controller initiates a corrective action modifying the operation of the delivery system when a predetermined pressure differential threshold is exceeded. The corrective action may include an increased air flow volume, an additional burst of higher pressure air into the conduit, a temporary increase in air flow from the air flow source, or a reduction in the rate of product flow from the supply chamber.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to agricultural equipment, and,more particularly to an agricultural product delivery system for anagricultural product such as seed, herbicide, insecticide and/orfertilizer entrained in an air stream, and to a method for equipmentoperation at near maximum product delivery rate while minimizing thelikelihood of delivery system blockage.

2. Description of the Related Art

Pneumatic agricultural product delivery systems utilize a flow of air toassist in the delivery and movement of particulate material or productsuch as fertilizer, seed, insecticide or herbicide from a product supplychamber to a growing medium, such as soil. Such pneumatic agriculturalparticulate material delivery systems are commonly employed in planters,air drills and a variety of other agricultural implements. Specialpurpose implements such as fertilizer application equipment, planters orair seeders may also employ pneumatic delivery systems. Known pneumaticagricultural product delivery systems typically use air in motion totransport the product through an interior passage provided by a seriesof elongate tubes which extend from the product supply chamber or hopperto an outlet adjacent to the soil. Various conditions may lead toproduct blockage in the tubes resulting in lost time and effort toremove the blockage and resume the agricultural process.

What is needed in the art is an air distribution system which minimizesblockage problems and can allow the equipment to run at near maximumdelivery capacity.

SUMMARY OF THE INVENTION

The present invention provides an agricultural product air distributionsystem which minimizes the likelihood of product blockage whilemaintaining product flow rate near maximum.

The invention in one form is directed to an agricultural implement forpneumatically distributing an agricultural particulate material, such asa fertilizer or seeds, as part of a crop production process. Theimplement has a transport unit movable on an agricultural field in alongitudinal direction and supporting a product supply chamber. There isa pair of product delivering booms extendable transversely to eitherside, each including a plurality of transversely extending conduits(conducts or tubes) of varying lengths terminating in productdistributing outlet nozzles. A mixing chamber receives air from an airflow source (fan) and product from the supply chamber to provide an airentrained flow of particles to each transversely extending conduit. Acontroller monitors product delivery and controls implement operation.Each conduit includes a pressure tap near the outlet nozzle forproviding the controller with a pressure differential indication for theconduit. The controller initiates a corrective action modifying theoperation of the implement when a predetermined pressure differentialthreshold indicative of imminent conduit blockage is reached. Thecorrective action may be a slowing of the ground speed of the transportunit by reducing engine speed or varying the implement transmissionratio either manually or using a specified protocol (ISOBUS protocol forexample). The corrective action may also be an increase in the air flowvolume (volume per unit time or air mass flow rate) from the air flowsource (fan), introduction of an additional burst of compressed air intothe conduit near the mixing chamber (various pressure variation patternsare possible), or a temporary increase in air flow from the air flowsource.

The invention in another form is directed to a process of monitoring anair/particle mixture movement through an elongated agricultural productdelivery system conduit to optimize the rate of product delivery. Theprocess includes measuring the pressure differential along the conduitand comparing that measured pressure differential with a predeterminedthreshold pressure differential. A corrective action is initiated whenthe comparison indicates imminent conduit blockage. The correctiveaction modifies the delivery system operation by reducing the rate ofagricultural product flow through the conduit or temporarily augmentingthe air flow in the conduit. The corrective action maintains productflow near maximum at all times without allowing the conduit to becomeblocked.

An advantage of the present invention is reduced down-time due toproduct clogging in delivery tubes.

Another advantage is maintenance of a near maximum product flow ratewhile distributing product.

Yet another advantage is optimum utilization of an agriculturalimplement having an air product distribution system.

BRIEF DESCRIPTION OF THE DRAWINGS

The above-mentioned and other features and advantages of this invention,and the manner of attaining them, will become more apparent and theinvention will be better understood by reference to the followingdescription of an embodiment of the invention taken in conjunction withthe accompanying drawings, wherein:

FIG. 1 is an isometric view of an air spreader system for agriculturalproducts such as fertilizer incorporating the invention in one form;

FIG. 2 is a top view of the air spreading system of FIG. 1;

FIG. 3 is an isometric view of the right boom of FIGS. 1 and 2;

FIG. 4 is an isometric view of a portion of the boom of FIGS. 1-3 from adifferent orientation including schematic controls;

FIG. 5 is a schematic illustration of the operation of the system ofFIG. 4; and

FIGS. 6A through 6D are graphs of exemplary air blast profiles for apneumatic product delivery system.

Corresponding reference characters indicate corresponding partsthroughout the several views. The exemplification set out hereinillustrates one embodiment of the invention, in one form, and suchexemplification is not to be construed as limiting the scope of theinvention in any manner.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawings, and more particularly to FIGS. 1 and 2,there is shown an agricultural implement 10 such as an air fertilizerspreader which generally includes a large tired transport unit such astruck or tractor, self propelled by an engine within the enginecompartment 12, and having a pair of laterally extending particledelivery booms 14 and 16. As is known in the art, these booms may bepivotable to a stowed position close to the implement for storage ortransport. Each boom includes a plurality of boom tubes or conductsterminating at the outboard end in a fertilizer spreading outlet ornozzle 18-32. Additionally, there are rear nozzles such as 31 and 33.The implement transport unit 34 includes an operator cab 36 and a pairof hopper compartments 38 and 39. The fertilizer spreader of FIGS. 1 and2 is illustrative and the invention may, of course, be employed inconjunction with other agricultural equipment such as tilling orplanting devices and is useful in distributing particulate materialother than fertilizer.

FIG. 3 shows the right (from the operator's viewpoint) boom 14 ingreater detail. It will be understood that the left boom 16 may be amirror image thereof. The inboard end of the boom includes a mixingchamber such as venturi box 40 which receives from an air flow source,such as a fan 42, an input air flow 44 to be mixed with a metered flow46 of fertilizer or other particulate material from a drop chute.Additional air flow from a compressor may be introduced automatically orunder operator control. The air and entrained particles are forced underair pressure down the individual boom tubes and from the nozzles ontothe agricultural field surface. Each boom tube or conduit includes anoutlet pressure tap 48-62 for providing an indication of the airpressure at that individual outlet to the control system. A similarupstream pressure tap 64 provides an indication of conduit inletpressure which may be considered as common to all the boom tubes or eachindividual tube may have its own inlet pressure tap.

As shown in FIG. 4, air inlet pressure tap 64 and outlet tap 48 arecoupled to a controller 66. Each pressure tap may include a transducerfor providing and electrical pressure indicative output to thecontroller, or air passageways from respective inlet and outlet taps maybe coupled to a pressure differential measuring device which, in turn,feeds pressure differential information to the controller. Thecontroller 66 provides outputs to the fan control 68, the pneumaticpressure source 70 and to a mechanism 72 for temporarily reducing theparticle flow 46 requirements from the hopper 74. The pneumatic pressuresource 70, such as a compressor with a conventional pressure tank oraccumulator, is normally inactive, but may be energized to provide atemporary burst of air into the conduit near the conduit inlet anddirected somewhat downstream when the pressure differential between thetaps 48 and 64 indicates incipient conduit blockage. This pneumaticsource may derive air pressure from air source (fan) 42 or may comprisean independent unit. The controller 66 may utilize a common inletpressure indication on line 76 or may receive individual conduit inletpressure information as indicated generally at 78, however, individualoutlet pressure information for each conduit as indicated at 80 isdesirable. Typically, pneumatic source 70 is dedicated to conduit 82with the other conduits receiving air bursts from further pneumaticpressure sources as triggered by signals on additional controller outputlines indicated generally at 84. The pneumatic source may be common toseveral or all conduits, in which case, those conduits will all receivea corrective burst of air.

In a preferred embodiment, the system has both a fan and an aircompressor. The pneumatic source (air compressor) 70 produces an airflow at a higher pressure than the fan 42. The fan runs continuously andthe air boost from the compressor air accumulator runs on demand at nearplugging conditions using various air pressure patterns. The system canalso speed up the fan to provide in general a larger air flow rate, butthe response time is slower than with the compressed air to break up awad of near-stopped particles.

The controller 66 operation is summarized in FIG. 5. The controllermonitors static pressure in each tube or conduit and provides theoperator with an indication thereof on in-cab display 86 that shows theair pressure drop (for example, in inches of H₂O). The operatortypically sets a plugging level and a level of tolerance percentage at88 and when the measured pressure drop (pressure differential) 90exceeds the set values, command 92 initiates the triggering 94 ofpneumatic pressure source for the offending conduit. Various patternsfor the air blast may be operator set as shown at 96.

Exemplary air blast patterns are shown in FIGS. 6A-6D. The blasts areshown as lasting 5 seconds, however, other blast durations may beemployed. FIG. 6A illustrates a blast having a relatively long period ofone-half second. FIG. 6C shows a more staccato-like repetition rateabout double that shown in FIG. 6A. A repetition rate intermediate thoseof FIGS. 6A and 6C is shown in FIG. 6B while a pattern random in bothrepetition rate and amplitude is shown in FIG. 6D. Other patterns andrates are clearly possible. Air blast patterns of a similar nature aredisclosed in the Roberge et al U.S. Pat. No. 8,651,927 B1. In thispatented arrangement, the air blasts are employed as part of an improvedcombine harvester separating and cleaning system. The avoidance ofresonance and shock waves in the conduits is an advantage of the randomair blast pattern.

The controller 66 is further operative to optimize the rate of productdelivery by measuring 90 the pressure differential along the conduit andcomparing 98 the measured pressure differential to a predeterminedthreshold pressure differential. When that threshold is reachedindicating imminent conduit blockage, a corrective action 100 isinitiated. The corrective action comprises modifying the delivery systemoperation by any suitable technique as by reducing the rate ofagricultural product flow through the conduit, for example, by reducingthe implement ground speed 102. Implement ground speed may be reduced byslowing the engine 12, or by varying the implement or traction unittransmission ratio either manually or utilizing any suitable protocollike ISOBUS. The corrective action may also include temporarilyaugmenting the air flow in the conduit as by increasing air flow 104from the fan 42, or providing a short air blast 106 from pneumaticsource 70. The fan 42 may temporarily provide the function of pneumaticpressure source 70 employing one or more solenoids to release air intoall or selected ones of the air boosters, but an air compressor ispreferred for its quick response time. The corrective action is intendedto maintain product flow near maximum at all times without allowing theconduit to become blocked.

While this invention has been described with respect to at least oneembodiment, the present invention can be further modified within thespirit and scope of this disclosure. This application is thereforeintended to cover any variations, uses, or adaptations of the inventionusing its general principles. Further, this application is intended tocover such departures from the present disclosure as come within knownor customary practice in the art to which this invention pertains andwhich fall within the limits of the appended claims.

What is claimed is:
 1. An agricultural implement for distributing anagricultural particulate material as part of a crop production processhaving a pneumatic product delivery system, the agricultural implementcomprising: a transport unit movable on an agricultural field in alongitudinal direction; at least one product supply chamber supported onand movable with the transport unit; a pair of product delivering boomsextendable transversely, one to each unit side, each boom including aplurality of transversely extending conduits of varying lengthsterminating in a product distributing outlet nozzle; an air flow source;a mixing chamber for receiving air from the air flow source and productfrom the supply chamber to provide an air entrained flow of particles toeach transversely extending conduit; a pneumatic pressure source influid communication with at least one conduit of the plurality ofconduits at a location downstream of the mixing chamber; a controllerfor monitoring product delivery and controlling implement operation; atleast one inlet pressure tap for determining a first pressure in atleast one of the plurality of conduits; each conduit including an outletpressure tap providing the controller with a pressure differentialindication for the conduit based on the first pressure at the at leastone inlet pressure tap and a second pressure at the outlet pressure tap;and the controller initiating a corrective action based on the pressuredifferential indication to slow the ground speed of the implement when apredetermined pressure differential threshold indicative of imminentconduit blockage in one or more conduits is reached.
 2. The agriculturalimplement of claim 1, wherein the ground speed of the transport unit isslowed by reducing engine speed.
 3. The agricultural implement of claim1, wherein the ground speed of the transport unit is slowed by varyingthe implement transmission ratio.
 4. The agricultural implement of claim1, wherein the particulate material is a fertilizer.
 5. The agriculturalimplement of claim 1, wherein the particulate material is seeds.
 6. Anagricultural implement pneumatic product delivery system, comprising; animplement supported product supply chamber; a pair of product deliveringbooms extendable transversely, one to each unit side, each boomincluding a plurality of transversely extending conduits of varyinglengths, each conduit terminating in a product distributing outletnozzle; an air flow source; and a mixing chamber for receiving air fromthe air flow source and product from the supply chamber to provide anair entrained flow of product particles to each transversely extendingconduit; a pneumatic pressure source in fluid communication with atleast one conduit of the plurality of conduits at a location downstreamof the mixing chamber; a controller for monitoring product delivery andcontrolling implement operation; at least one inlet pressure tap fordetermining a first pressure in at least one of the plurality ofconduits; each conduit including an outlet pressure tap providing thecontroller with a pressure differential indication for the conduit basedon the first pressure at the at least one inlet pressure tap and asecond pressure at the outlet pressure tap; and the controllerinitiating a corrective action based on the pressure differentialindication to slow the ground speed of the implement when apredetermined pressure differential threshold in one or more conduit isreached.
 7. The pneumatic product delivery system of claim 6, whereinthe ground speed of the transport unit is slowed by reducing enginespeed.
 8. The pneumatic product delivery system of claim 6, wherein theground speed of the transport unit is slowed by varying the implementtransmission ratio.
 9. An agricultural implement pneumatic productdelivery system, comprising: a plurality of transversely extendingconduits; an air flow source; a product supply chamber; a mixing chamberfor receiving air from the air flow source and product from the supplychamber to provide an air entrained flow of particles to eachtransversely extending conduit; a pneumatic pressure source in fluidcommunication with at least one conduit of the plurality of conduits ata location downstream of the mixing chamber; a controller for monitoringproduct delivery through the plurality of conduits; the controller beingconfigured to initiate a corrective action to slow the ground speed ofan associated implement when a predetermined pressure differentialthreshold indicative of imminent conduit blockage is reached, whereinthe pressure differential is measured with at least one inlet pressuretap and at least one outlet pressure tap located in at least one of saidconduits.
 10. The agricultural implement pneumatic product deliverysystem of claim 9, wherein the ground speed of the transport unit isslowed by reducing engine speed.
 11. The agricultural implementpneumatic product delivery system of claim 9, wherein the ground speedof the transport unit is slowed by varying the implement transmissionratio.